In high capacity optical communications systems, a plurality of channels, each comprising a relatively low bit-rate optical pulse stream, are time division multiplexed into a high bit-rate pulse stream. For example, a plurality of relatively low bit-rate optical soliton pulse streams may be combined into a single high bit-rate optical soliton pulse stream. This multiplexing of data streams, of course, requires that there be a subsequent effective demultiplexing of the high bit-rate data into lower-rate data, for example, demultiplexing 10 to 20 Gbit/sec. data to the well-known 2.5 Gbit/sec. SONET rate.